ABCA4 and age-related macular degeneration: For example, all-trans retinaldehyde transporter (ABCA4), hemicentin (HMCN1), an extracellular protein involved in epithelial cell junction formation, multiple complement-related proteins (CFH and C3), age-related maculopathy susceptibility gene 2 (ARMS2) and apolipoprotein E (APOE) are all associated with the development of AMD [67].